JP3946453B2 - Heat resistant bottle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat-resistant bottle.
[0002]
[Problems to be solved by the invention]
A small-capacity bottle of about 350 ml in which the contents are heated and filled has been commercially available, but there was no hexahedral bottle with a hexagonal cross section in which the shoulder and the bottom were circular and the body was chamfered.
The main reason for this is that with a small-capacity heat-resistant bottle equipped with a vacuum absorption panel, if the body is a hexahedron, the vacuum absorption panel surface cannot be made large, and the amount of vacuum absorption is small, so the contents can be reduced. The heat sterilization up to about 90 ° C and the heat filling cannot be performed.
[0003]
In order to enlarge the vacuum absorbing panel surface, it has been proposed to lengthen the length of the body and lower the height of the shoulder, but it has been proposed that the conventional two methods of stretching in the axial direction followed by stretching in the radial direction. Axial stretch blow has a problem that the thickness of the lower end portion of the shoulder portion becomes thin and deforms due to reduced pressure during cooling.
[0004]
In addition, 500ml-1000ml hexahedral heat resistant bottles are well known in the art. However, when heated and filled at a high temperature of 90 ° C or higher, conventional biaxial stretch blow reduces the thickness of the lower end of the shoulder. When a slight impact is applied during cold temperatures, there is a problem that the shoulder is deformed.
[0005]
The present invention solves the above problems and provides a square heat-resistant bottle having a thickened shoulder portion and reinforcing the shoulder portion, particularly around 350 ml in which the shoulder portion is reinforced and the vacuum absorbing panel is widened. An object is to provide a heat-resistant bottle.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is a heat-resistant bottle comprising a mouth portion and a shoulder portion, a trunk portion and a bottom portion, and a biaxial stretch blow-molded heat-resistant bottle, wherein the shoulder portion and the trunk portion are A laterally concave rib is arranged at the boundary, and the height of the shoulder is the height from the bottom surface of the neck ring to the bottom upper end of the laterally concave rib, and 0.19 to the height from the bottom end to the shoulder upper end The body portion is formed by upper and lower cylindrical surfaces and a square wall surface having a corner having a circular arc surface and a vacuum absorbing panel in the center, and the rib bottom diameter of the laterally concave rib is defined as the body portion. The configuration is characterized in that the thickness is 0.85 to 0.92 with respect to the outer diameter of the cylindrical surface, and the thickness of the lower end of the shoulder is increased.
[0007]
In order to widen the vacuum absorbing panel, a configuration is adopted in which the square wall surface of the body portion is 4 to 10 planes, particularly a 6 to 8 plane body.
[0008]
As a stretch blow molding method for heat-resistant bottles, a configuration is adopted in which a blower is blown simultaneously with the operation of the stretching rod , and biaxial stretch blow molding is performed so as to perform radial stretching and axial stretching simultaneously. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, Ao is a heat-resistant bottle formed by biaxial stretch blow molding using PET or other synthetic resin, filled with an edible liquid that has been sterilized by heating at around 90 ° C. or higher, It consists of a shoulder 2, a body 3 and a bottom 4.
[0010]
The mouth portion 1 is provided with a screw 5 and a neck ring 6, and the lower portion of the neck ring 6 continues to the shoulder portion 2.
The shoulder 2 is formed by a large number of triangular curved panels 7 facing vertically, and a laterally concave rib 8 is disposed at the boundary with the trunk 3.
[0011]
The body portion 3 includes a short cylindrical surface 9 following the laterally concave rib 8, a hexagonal portion 12 having a corner portion formed by an arcuate surface 11 with a reduced pressure absorption panel 10 disposed on each surface, and a short cylindrical surface 13 at the lower end thereof. It is made up of.
At the boundary between the body portion 3 and the bottom portion 4, laterally concave ribs 14 following the cylindrical surface 13 are disposed. The bottom 4 includes a peripheral wall 15, a bottom end wall 16, and a bottom wall 17 provided with a plurality of vertical ribs.
[0012]
The bottle of the present invention employs a specific stretch blow molding method in order to prevent the lower end of the shoulder from becoming thin.
The method will be described with reference to FIG.
In FIG. 2, 20 is a blow mold comprising two split molds 20a and 20b and a bottom mold 20c, 21 is a core guide, 22 is a neck support, and 23 is an extending rod having an air passage 24 carved on the circumference. , P is a preform.
[0013]
Stretching blows compressed air and starts operation of the stretching rod 23 almost simultaneously. As shown by a two-dot chain line in FIG. 2, when the stretching rod 23 is protruded by a certain distance, the preform P is The base portion resin p1 is expanded in the radial direction so as to be in contact with the shoulder portions of the split molds 20a and 20b.
And the front-end | tip of the extending | stretching rod 23 contacts the bottom part metal mold | die 20c, and with the completion of extending | stretching of an axial direction, high-pressure air is blown and the extending | stretching of the radial direction of the whole bottle is completed, and a biaxial stretching blow bottle is shape | molded. .
[0014]
In molding, the resin of the preform P is hooked on the convex rib 8A portion by reducing the bottom diameter of the lateral concave rib 8 and increasing the protruding amount of the convex rib 8A protruding inward of the blow mold 20, A large amount of resin remains on the entire shoulder portion, and the thickness of the shoulder portion can be increased.
[0015]
The illustrated bottle is a heat-resistant bottle of 350 ml, the rib bottom diameter A of the laterally concave rib 8 is 61 mmφ, and the diameter B of the cylindrical surface 9 of the body 3 is 66 mm.
The height C of the shoulder portion, that is, the height from the bottom of the neck ring 6 to the bottom upper portion 8a of the transverse concave rib 8, is the height from the bottom end wall to the neck ring 6, that is, the bottom end to the shoulder The height D to the upper end of the part is 141.6 mm.
In other words, the length of the body portion, that is, the length from the bottom upper portion 8a to the bottom end of the horizontal concave rib 8 is set to 108 mm, which is long.
[0016]
The effect on the wall thickness distribution due to the rib bottom diameter A of the lateral concave rib 8 being φ61 mm was confirmed through tests.
In the test, two bottles having different rib bottom diameters A formed by the stretch blow were compared.
Each bottle has a shoulder 2 of C = 33.6 mm, D = 141.6 mm, B = 66 mm, a bottle with a rib bottom diameter A of φ61 mm, and a bottle with a rib bottom diameter A of φ62.5 mm The wall thickness of the trunk | drum 3 was measured and the distribution state was compared.
As a result, a graph of the distribution state as shown in FIG. 3 was obtained.
[0017]
From the measurement effect, when the rib bottom diameter A is φ62.5 mm, the wall thickness of the lower end portion of the shoulder portion 2 was 0.32 mm, but when the rib bottom diameter A was reduced to φ61 mm, the shoulder portion The thickness of the lower end of 2 is 0.43 mm, and the entire shoulder 2 is thick.
[0018]
Accordingly, when the rib bottom diameter A is large and the protruding amount of the convex rib 8A of the blow mold 20 is small, the resin of the preform P flows toward the bottom without being caught by the convex rib 8A portion. On the other hand, when the protruding amount is large, it can be understood that the resin is caught by the convex rib 8A portion and the flow is prevented.
When the rib bottom diameter A is reduced and the protrusion amount is increased, the effect of preventing the flow is increased, so that A = φ61 mm or less confirmed as a result of the test and the diameter B = φ66 mm of the cylindrical surface 9 of the trunk portion, 0.92 or less is preferable.
Regarding the lower limit of A, considering the bottle design, A = φ56 mm and A / B = 0.85 can be taken.
[0019]
Next, the length of the body portion 3 will be described. In order to take a reduced pressure absorption surface, the length of the body portion 3 is preferably as large as possible. The 20 protruding ribs 8 </ b> A projecting portions are brought into contact with each other, so that the thickness of the shoulder portion 2 is increased.
In the embodiment, the length of the body 3 is 108 mm, C = 33.6 mm, and D = 141.6 mm. However, C is further shortened to C = 27 mm and C / D = 0.19. May be.
Therefore, the dimensional ranges of A, B, C, and D can be A / B = 0.85 to 0.92, and C / D = 0.19 to 0.25.
[0020]
The dimensions of the above parts are related to heat-resistant bottles with a capacity of 350 ml and a body part of hexahedron, but the above-mentioned dimensional ratio can be applied to 4- to 8-hedron bottles with heat-resistant bottles with a small capacity of around 350 ml. In particular, in the case of a decahedron bottle, the size of the vacuum absorbing panel on each side is small, so the use of the above dimensional ratio is effective.
[0021]
Further, in relation to the capacity of the bottle, by reducing the bottom diameter of the laterally concave rib and adopting the molding method, the thickness of the lower end portion of the shoulder portion can be increased and the entire shoulder portion can be increased in thickness.
As a result, the shoulder portion is reinforced, so that even in a heat-resistant bottle of 500 to 1000 ml, the heating temperature of the content liquid is raised and the shoulder portion is prevented from being deformed when stored under refrigeration below room temperature. Can do.
[0022]
【The invention's effect】
Since this invention is comprised as mentioned above, there exists the following effect.
The bottle of the present invention is provided with a horizontal concave rib at the boundary between the shoulder portion and the trunk portion, the diameter of the rib bottom of the horizontal concave rib is reduced, and decompressed air is blown simultaneously with stretching, and the preform resin is injected into the horizontal concave rib. It was possible to prevent a reduction in the thickness of the shoulder portion by catching on the convex rib portion of the blow mold corresponding to the above.
[0023]
As a result, shoulder deformation due to reduced pressure can be eliminated, the body can be lengthened, and the reduced pressure absorption panel can be widened. In a heat-resistant bottle with a small capacity of 6-octahedron, heating at about 90 ° C or higher is possible. Filling is now possible.
Moreover, even in a 500 to 1000 ml heat-resistant bottle, the shoulder portion can be reinforced, and heating and filling can be performed at a higher temperature.
[Brief description of the drawings]
FIG. 1 is a front view of a bottle of the present invention.
FIG. 2 is an explanatory diagram of the behavior of a preform during molding.
FIG. 3 is a thickness distribution diagram according to a difference in rib bottom diameter.
[Explanation of symbols]
Ao Bottle A Rib bottom diameter B Cylindrical surface diameter C Shoulder height D Height from bottom end to shoulder top P Preform P1 Base part resin 1 Mouth part 2 Shoulder part 3 Body part 4 Bottom part 5 Screw 6 Neck Ring 7 Curved panel 8 Horizontal concave rib 8A Convex rib 8a Bottom upper part 9 Cylindrical surface 10 Decompression absorption panel 11 Arc surface 12 Hexahedral part 13 Cylindrical surface 14 Horizontal concave rib 15 Peripheral wall 16 Bottom end wall 17 Bottom wall 20 Blow mold 20a, b Double die 20c Bottom die 21 Core guide 22 Neck support 23 Stretching rod 24 Air passage

Claims (3)

It consists of a mouth and shoulders, a body and a bottom, and is a heat-resistant bottle that is biaxially stretch blow molded,
A laterally concave rib is arranged at the boundary between the shoulder and the trunk,
The height of the shoulder is the height from the bottom surface of the neck ring to the bottom upper end of the laterally concave rib, and is 0.19 to 0.25 relative to the height from the bottom end to the shoulder upper end,
The body portion is formed by upper and lower cylindrical surfaces and a square wall surface with a corner portion being an arc surface and a vacuum absorbing panel provided at the center,
A heat-resistant bottle, wherein the rib bottom diameter of the laterally concave rib is 0.85 to 0.92 with respect to the outer diameter of the cylindrical surface of the body portion, and the thickness of the lower end portion of the shoulder portion is increased.   The heat-resistant bottle according to claim 1, wherein the square wall surface of the trunk is a 6-8 octahedron.   The heat-resistant bottle according to claim 1 or 2, wherein a blower is blown simultaneously with the operation of the stretching rod to perform biaxial stretching blow molding so as to perform radial stretching and axial stretching simultaneously.

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